Antidepressant drug could ease long COVID brain fog and fatigue
NCT ID NCT05874037
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This completed trial tested whether fluvoxamine, an FDA-approved drug for OCD, can improve long COVID symptoms like trouble concentrating, anxiety, depression, and fatigue. 191 adults from Missouri and Illinois who had COVID at least 3 months earlier took either fluvoxamine or a placebo. Participants rated their symptoms daily to see if the drug helped reduce their severity.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Fluvoxamine
- What this could lead to
- If it works, this could point toward a treatment for long COVID symptoms like fatigue, anxiety, and trouble concentrating.
- What could go wrong
- This is a small, completed trial with 191 participants, so results may not apply to everyone. Fluvoxamine is an antidepressant, and its benefits for long COVID are not proven yet.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 2/3
Runs two stages together: whether the treatment works, then large-scale confirmation.
- Participants
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191 people
The number who actually took part.
- Started
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May 2023
- Finished
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Mar 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
25 years and older
- Sex
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Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Men and woman age 25 and older; 2. Not currently hospitalized 3. Participant self-report of past acute COVID episode with symptom onset and/or initial positive test at least 3 months since initial COVID symptoms and/or test confirming SARS-CoV-2 infection Note: Since some people with long COVID may not have been able to obtain testing during the acute phase of illness, history of a positive COVID-19 test is not required. We will collect data regarding the results of any past COVID-19 testing, but this will not affect eligibility for the trial. 4. Currently symptomatic with self-reported worsening of cognitive function for at least the past 2 months, that could not be better explained by other reasons (i.e. alternative diagnosis or medication changes). 5. Able to provide informed consent. 6. Currently reside in Missouri or Illinois Exclusion Criteria: 1. Illness severe enough to require hospitalization at the time of starting the study. 2. Unstable medical comorbidities (eg decompensated cirrhosis), per patient report and/or medical records. 3. Immunocompromised from the following: solid organ transplant, BMT, high dose steroids (\>20mg prednisone per day), or tocilizumab 4. Already enrolled in another COVID 19 medication trial (not including vaccination or prophylaxis trials) 5. Unable to provide informed consent 6. Unable to perform the study procedures, including not being a resident of the states of Missouri or Illinois 7. Taking donepezil (rationale: donepezil is a S1R agonist), or sertraline (rationale: sertraline is a strong sigma-1 antagonist). 8. Taking phenytoin (rationale: fluvoxamine inhibits its metabolism), clopidogrel (rationale: fluvoxamine inhibits its metabolism from pro-drug to active drug which raises risk of cardiovascular events), and St John's wort (rationale: fluvoxamine + St John's wort are considered contraindicated because of the risk of serotonin syndrome) 9. Taking SSRIs or SNRIs. 10. Individuals who report they have bipolar disorder or are taking medication for bipolar disorder (lithium, valproate, high-dose antipsychotic), unless the investigator concludes that the risk for mania is unlikely (ie it is doubtful that the patient actually has bipolar disorder). 11. Individuals who take alprazolam or diazepam and are unwilling to cut the medication by 25% (rationale: fluvoxamine modestly inhibits the metabolism of these drugs). 12. Participants taking theophylline, tizanidine, clozapine, or olanzapine (drugs with a narrow therapeutic index that are primarily metabolized by CYP 1A2, which is inhibited by fluvoxamine) will be reviewed with a study investigator and excluded unless the investigator concludes that the risk to the participant is low (this would be unlikely; example: participant takes tizanidine only as needed and is willing to avoid it during study duration).
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Washington University School of Medicine
St Louis, Missouri, 63110, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
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